1. Field of the Invention
This invention generally relates to printing systems which print out text stored in a buffer. More specifically, this invention relates to a system for controlling the output side-by-side printing of sequentially stored columns having varying printer font requirements.
2. Description of Prior Art (Prior Art Statement)
Representative of the closest known prior art are U.S. Pat. No. 3,952,852; the IBM Electronic "Selectric"* Composer; U.S. patent application Ser. No. 680,562, filed Apr. 27, 1976 having Michael E. McBride as inventor and entitled Automatic Format Control for Text Printing System, now U.S. Pat. No. 4,086,660, issued Apr. 25, 1978; and IBM Technical Disclosure Bulletin (TDB), Vol. 13, No. 5, October 1970, pages 1149 and 1150. FNT *Registered Trademark, International Business Machines Corporation.
In U.S. Pat. No. 3,952,852 a system is disclosed having basically a keyboard and printer, a buffer and control, and a multi-column playout control unit. During setup for input keying, a beginning of memory code is stored in the buffer. Also, since the input printer is the same as the output printer, a tab field is set up for defining the locations in which the columns are to be located. For columns which are to be keyed and stored sequentially, but printed out in a side-by-side manner, the beginning of each column is defined by the keying and storage of a column begin code. Each column is then keyed and stored in its entirety. At the end of the last column to be printed out in a side-by-side relationship, a column end code is keyed and stored. Upon playout from the buffer, the buffer memory established as described above is scanned when a column begin code is encountered. An operation flag is inserted into the buffer code memory after the first column begin code. After each column begin code except the first, a column marker code is inserted and scan continues. Upon detection of the column end code, scanning continues to the beginning of memory. When the operation flag is again detected, following characters and spaces are printed out in the defined mode until a carrier return is detected. The operation flag is advanced beyond the carrier return code, the printer is caused to tab rather than to return the carrier to the left margin, and a column advance operation is performed. This causes a column marker code to be written over the operation flag, and a scan of memory. The next detected column marker code is written over with a new operation flag. Printout then continues beginning at the point of the new operation flag until a carrier return is detected. The playout operations described continue until the end of each column is reached. After printout of all columns, the column marker codes are flushed from memory.
From the above, the side-by-side printout of sequentially stored text is fully disclosed, but system responsiveness to font change requirements has not been addressed.
Consider next the IBM Electronic "Selectric" Composer. If during a side-by-side printout of sequentially stored columns a change in the printer font is required from one column to another to accommodate a change in printing style or language group, the operator must have planned accordingly during input keying. That is, a special (stop) code must have been keyed and stored in memory at the beginning of each line of the column(s) to be affected. Upon printout from the memory, the system will recognize each stop code and cease printing. Thereafter, the operator will change fonts and start the printing operation again. The keying of stop codes for each line is extremely time consuming and tedious. Also, the keying position in terms of placement of stop codes requires a great deal of thought in applications requiring many and varied font changes. Further, the keyed and stored text cannot be adjusted without clearing the stop codes from memory.
Based on the above, the IBM Electronic "Selectric" Composer, although capable of automatically stopping during a side-by-side printout of sequentially stored columns, is not readily adaptable to printer font change requirements when throughput is a major consideration.
In the above-referenced McBride patent application, an automatic system is disclosed for controlling format during playout of a job made up of a number of pages recorded on a number of magnetic cards. At the beginning of a job and upon input keying, format information is keyed and stored in a text buffer. The format information is made up of tab set locations, measure length, index values, adjust modes, etc. For format changes prior to recording on a magnetic card, new format information is keyed and stored in the text buffer along with keyed text. Upon recording the text and format information on a card, the format information last in effect is transferred to a format buffer to control format until changed. Likewise, for later playout of text stored on magnetic cards, the format information last in effect will control format until changed.
This prior art is relevant in that different printer requirements from one segment to the next are readily handled. In the case of the instant application though, the segments are different columns stored in the same medium, whereas in the referenced McBride application, the segments are related to different media. Further, neither font changing nor side-by-side printout are addressed in the McBride application. Even if font changes are considered format changes, not addressed is the efficient handling of different printer font requirements within a segment which is operated upon only one line at a time. That is, in the instant application operation within any given column is only one line at a time in that an entire print line is completed with corresponding text from all columns before operation can resume in the given column.
The above-referenced IBM TDB discloses an automatic font changer responsive to operator stored codes. Although particularly relevant in the area of causing the printer to stop upon a font change code, not addressed are side-by-side printout of sequentially stored columns and the storing of the font requirements when printing from one column to another, one line at a time.
In summary, the above described art is relevant to varying degrees, but falls short of either anticipating or rendering the subject invention obvious. More specifically, the subject invention presents an advance over the prior art in terms of a system structured to effect a side-by-side playout of sequentially stored columns having font requirements stored therewith, separately store effective changes in font requirements, and respond to these changes. Some of the more important advantages of such a system are that operator coding during input keying is minimized, and there will be no cessation of printing if an intermediate column requiring a different font does not contain information to be printed.